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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_1365_Библиотеки_им_академика_М_И_Перельмана.pdf
Chapter 10
Lower Esophageal Sphincter Efcacy
Following Laparoscopic Antireux Surgery
withHiatal Repair: Role ofFluoroscopy,
High-Resolution Impedance Manometry
andFLIP inDetecting Recurrence ofGERD
andHiatal Hernia
VivienWong, BarryMcMahon, andHansGregersen
10.1 Introduction
Gastroesophageal reux disease (GERD) is a global public health problem affecting
more than 20% of the population. Hiatus hernia, a quite frequent condition in
elderly, is known to be an important risk factor for the development of GERD.In
subjects who are symptomatic hiatal hernia promotes gastric acid access to the
esophagus and impairs its clearance. The overall consequence of increased esophageal acid exposure is reux esophagitis. Medical therapy with PPI is the rst choice
of treatment but does not help all patients. The rst surgical repair for hiatus hernia
was reported by Soresi in 1926 [1]. Since then there have been many diagnostic and
therapeutic advancements but there is still a need for development of current techniques due to the physiological and anatomical complexity of the region. The
esophago-gastric junction (EGJ) has a complex anatomical and mechanical function
in normal subjects as well as in patients with hiatus hernia, and in those with surgically repaired EGJ and hernia (see later).
Efcacy is the ability to produce a desired result or effect. Speaking about the
lower esophageal sphincter (LES), efcacy under physiological conditions as well
as pathophysiological conditions such as in herniation and after hiatus repair relates
to its ability to avoid any pathological consequences of reux of gastric contents.
These complex issues will be discussed later in the chapter. Firstly, LES is part of a
V. Wong • H. Gregersen (*)
Department of Surgery, Prince of Wales Hospital,
4/F, Clinical Science Building, Shatin, NT, Hong Kong
e-mail: hag@giome.org
B. McMahon
Trinity Academic Gastroenterology Group, Trinity College, Dublin, Ireland
M.A. Memon (ed.), Hiatal Hernia Surgery,
https://doi.org/10.1007/978-3-319-64003-7_10
153© Springer International Publishing AG 2018
154
V. Wong et al.
wider barrier mechanism to prevent reux of gastric contents into the esophagus.
Other structures such as the crura of the diaphragm and the FLAP valve contribute
to the barrier mechanism as well. The anatomy gets even more complicated when
normal tissues structures are remodeled such as in herniation and when surgical or
endoscopic fundoplication procedures are carried out. Secondly, efcacy can be
evaluated in terms of several variables and parameters including symptoms, pH in
esophagus, EGJ pressure proles, clearance, and ow through the EGJ.Therefore,
diagnostic technologies such as hypersensitivity testing, high-resolution manometry (HRM), intraluminal impedance, pH-metry, uoroscopy, functional luminal
imaging (FLIP) and endoscopy are relevant and of value. However, we may not
fully comprehend how these tests complement each other.
This chapter provides an insight into the complex anatomy and physiology of the
EGJ including the LES under normal conditions and under remodeled conditions as
observed in herniation and during operational procedures. The chapter deals in particular with efcacy evaluation of the surgical repair and recurrence based on uoroscopy, impedance manometry, and FLIP.
10.2 Anatomy oftheEGJ
The EGJ consists of several structures that regulate transport of swallowed substances to the stomach and serves as a barrier against reux of gastric contents
[2, 3] (Fig.10.1). The reux barrier is predominantly maintained by the LES and the
crural bers of the diaphragm [4, 5].
LES is a tonically contracted segment of the EGJ that together with the clasp and
sling bers of the gastric cardia form an integrated sphincter mechanism [2, 3]. LES
anatomy is fascinating since a distinct anatomical sphincter with muscle thickening
has not been clearly identied [2, 3, 6, 7]. Rather, manometric studies have shown
Fig. 10.1 The anatomy of
the normal esophagogastric junction showing
the esophagus, stomach,
diaphragm and the clasp
and sling bers (modied
and reproduced with
permission from ref. [2])
Esophagus
Right cruz
Diafraghm
Gastric sling fibers
Gastr
Esophageal clearance¯
10 Lower Esophageal Sphincter Efcacy Following Laparoscopic Antireux Surgery
155
the high-pressure zone in the lower esophagus [8, 9]. LES is not an annular sphincter but rather formed by two crossing muscle bundles, i.e. the semicircular “clasp”
and the oblique “sling” muscular bers derived from the oblique bers of the stomach [2, 3, 6, 7, 10]. Closure of the EGJ appears to be due to contraction of these
muscle bundles in conjunction with crural bers of the diaphragm [7, 9, 11–16].
Another important anti-reux structure is the gastroesophageal ap valve formed
by a musculo-mucosal fold that maintains a pressure gradient between the stomach
and lower esophagus to keep gastric contents away from the EGJ [3, 14, 17–21].
The sling bers of the stomach located below the LES are associated with a valve
mechanism whereby pressure in the gastric fundus creates a ap that presses against
the lower end of the esophagus [20].
The gastroesophageal ap valve is located at the gastric cardia where it maintains
the acute angle of His [7, 20].
Brasseur and co-workers described three distinct components of the barrier
mechanism in the gastro-esophageal segment and how they can be differentiated.
The components are the extrinsic crural sphincter and the intrinsic LES and sling/
clasp muscle unit. Efcacy is maintained by a delicate interplay between the components [22].
Hiatus hernia is characterized by proximal displacement of the EGJ causing the
intrinsic sphincter to lie proximal to the hiatus formed by the crural diaphragm [23]
(Fig.10.2). This is likely caused by rupture or weakening of the phreno-esophageal
ligament [25]. Patients with hiatus hernia have more reux episodes and greater esophageal acid exposure than patients without hiatus hernia and they have more severe
esophagitis [26]. Furthermore, larger hiatal hernia is associated with a greater esophageal acid exposure and prolonged acid clearance times [27]. This is likely a reection
of the remodeled mechanical properties of the barrier mechanism [28]. Referring again
to the work by Brasseur, hiatus hernia with its distinct mechano- morphometric changes
disrupts the integrity of the physiological barrier mechanism [22].
Surgical or endoscopic fundoplication aims to restore the lost efcacy observed
in herniation. The geometry of the EGJ and mechanically defect LES can be somewhat restored by antireux surgery. The LES length and the FLAP valve are to some
degree regenerated which increases the baseline LES pressure [29]. In addition to
the contribution to the pressure increase, the lengthened LES better resist the effect
LES dysfunction
Hiatal hernia
Crural diaphragm dysfunction
ic volume and emptying
Pyloric dysfunction
Fig. 10.2 Mechanisms contributing to reux disease including the hiatal hernia (reproduced with
permission from ref. [24])
156
of gastric wall tension in opening the LES.This is complemented by the recreation
of the FLAP valve which tends to occlude the lumen and increase pressure [30]. If
the wrap is defect or recurrence occur, then the full geometric-mechanical effect is
not obtained and efcacy will be impaired.
V. Wong et al.
10.3 Physiology ofEsophago-Gastric Junction
withFocus onLES Efcacy
From studies performed up to 20years ago and summarized elegantly by reviews
from Mittal & Balaban [3] and Kahrilas [31], it is evident that the core tenants of the
barrier function at the EGJ are now well established. The thickened muscle area at
the distal end of the esophagus represent the LES intrinsic barrier whereas the diaphragmatic hiatus, which is located as a narrow opening in the diaphragm where the
distal esophagus exits the thoracic cavity and enters the abdominal cavity, represents an extrinsic barrier. Studies indicate that the proximal 2cm of the 4cm-long
LES is where the so-called extrinsic “pinch cock” effect of the diaphragm overlaps
the intrinsic circular valve effect of the LES [32]. The physiology described in these
reviews still forms the basis for surgical treatment options as mentioned in the
recent review by Patti and coworkers [33].
The role of the LES at the EGJ has been quite well understood for a considerable
time. In normal subjects the LES exerts a circular muscle force at the distal end of
the esophagus just as it enters the stomach. This is part of the barrier that ensures
stomach contents do not travel back into the esophagus. When swallowing is initiated the LES relaxes allowing ingested material to travel from the esophagus into
the stomach [34]. Much of our understanding of this comes from manometric studies. These type of studies were further enhanced in the 1970’s by Dent and coworkers, who using a variant of manometry known as the Dent sleeve, demonstrated
that the LES relaxes at other times as well [35]. These events are known as transient
lower esophageal sphincter relaxations (TLESRs). It has been shown that the number of transient relaxations is higher in patients suffering from GERD [32].
The more recent work of Miller and Brasseur used a very precise manometric pullthrough technique concurrent with high frequency ultrasound and studied the highpressure zone at the EGJ [22]. Their aim was to separate and manometrically quantify
invivo the skeletal and smooth muscle components at the EGJ in an attempt to gather
more physiological detail in the LES region. This was achieved using atropine in one
group of healthy volunteers to suppress the cholinergic smooth muscle sphincter
effect and cistracurium in another group to neuromuscularly block the crural sphincter. Hence, the muscle contributions could be studied separately. The main and signicant nding from this study is that the pressure proles generated by manometric
pull-through of the region, if carried out with great precision and with the interventions above, can obtain more information on the physiology and function of the LES.
From this work new information that suggests the LES has two subcomponents
is evident. The authors conclude that one component is a proximal smooth muscle
component. They describe this as the lower esophageal circular muscle, which tends
10 Lower Esophageal Sphincter Efcacy Following Laparoscopic Antireux Surgery
to move with the movement of the crural diaphragm component probably due to its
attachment to the phreno-esophageal ligament. The other component is described as
the smooth muscle component distal to the diaphragm and from ultrasound appeared
to be located approximately at the position of the sling-clasp muscle bers [36].
157
10.4 Laparoscopic Antireux Surgery withHiatal
Repair Surgical Aspects
The anti-reux effect of fundoplication was discovered after a 16-year follow-up of
a patient with partial esophagectomy done using a fundoplication wrap around the
anastomosis with the purpose of preventing leakage [37]. It became the most commonly practiced effective surgical treatment for GERD.However, how the procedure has augmented the effect of the lower esophageal complex to act as a valve
against reux is still under discussion.
Fundoplication is shown to increase the nadir lower esophageal pressure [38, 39]
and thereby better resists the intra-gastric pressure that produces reux, while preserving its ability to relax (though less completely) upon wet swallows [38]. While
this increase in pressure is shown to be exerted by the gastric wrap in animal studies
excluding the LES by myotomy [40], the fact that this new high pressure zone
behaves similarly to the physiological LES is interpreted as improvement of the
LES smooth muscles by some authors [41].
The relaxation pattern of the LES is also altered after fundoplication. Increased
TLESR is found in many patients with GERD [42–45]. The relaxation is initiated
by gastric cardiac distension, the most sensitive zone as shown in animal studies
[46]. The fundoplication wrap alters the distensibility at the region. Ireland and
coworkers have demonstrated a signicant decrease in TLESR frequency detected
after fundoplication and gastroesophageal reux associated with the episodes [39].
10.5 Recurrence ofGERD andHiatal
Hernia Clinical Features
10.5.1 Clinical Features andFundoplication Failures
The rate of long-term resumption of acid-reducing medication after fundoplication is
shown to vary widely from 5.8 to 62%, with most reports showing a rate of <20% [47].
Level I evidence showed a symptom resolution rate of 67% at 7-year follow up [47].
Recurrence with new reux symptoms usually indicates a breakdown of the fundoplication [48]. A systematic review on surgical re-intervention after anti-reux surgery showed
that over 80% of failed procedure is due to disruption of the post- operative anatomy [49].
Upon symptom recurrence after fundoplication, the approach to investigate for
indication of re-operation is similar to that for the primary procedure. Investigations
158
ab
V. Wong et al.
aim to show objective evidence of acid reux recurrence and to show the integrity
of the previous repair. Most patients who received re-operations were worked up
with endoscopy, uoroscopy and/or pH monitoring studies [49]. In particular,
endoscopy and uoroscopy help visualize the status of the wrap and hiatal repair.
A successful anti-reux surgery comprises of a proper fundoplication and an
intact hiatal hernia repair. Various types of fundoplication wrap disruptions have
been described [50], according to the status of the wrap itself and the presence of
any recurrence of the hiatus hernia. The wrap can be incompetent due to loosening
or breakdown, or intact but slipped so part of the stomach is herniated through the
wrap. Hiatus hernia may recur in any of the scenarios, and the wrap itself may also
herniate through the diaphragm (Fig.10.3).
c
Fig. 10.3 Types of fundoplication failure (reproduced with permission from ref. [50]). (a)
Complete or partial wrap disruption with or without recurrence of the hiatus hernia. (b) Hiatal
herniation of the stomach via the intact fundoplication wrap. (c) Slippage of the wrap causing
gastric herniation through the wrap only but not the diaphragm. (d) Hiatal herniation of the intact
fundoplication wrap
d
10 Lower Esophageal Sphincter Efcacy Following Laparoscopic Antireux Surgery
159
10.5.2 Role ofFluoroscopy
Barium esophagography is a simple investigation that allows surgeons to assess the
morphology of the wrap, albeit interpretation can be challenging even for radiologists unless full understanding of the surgical procedure itself is acquired [51].
Double-contrast study is preferred. Three components can be observed: (1) the
wrap, (2) hiatus hernia, and (3) presence of reux. Barium esophagogram after
fundoplication would show a smooth well-circumscribed lling defect at the gastric
fundus surrounding the narrowed distal esophagus, located below the diaphragm.
The wrap can occasionally be lled with barium contrast (Fig. 10.4). Normally,
above the wrap would be the esophagus and below the stomach. A slipped wrap
would show the presence of the gastric fundus above the wrap (Fig.10.5). Noting
the level of diaphragm, recurrence of hiatus hernia can be identied, even in the
case of herniation of the whole wrap (Fig.10.6). Occasionally, contrast reux is
observed during uoroscopy, conrming the presence of an incompetent LES.
In the situation of reux recurrence after fundoplication, endoscopy (esophagogastroduodenoscopy) is another important investigation. It plays the role of identifying failed procedure and ruling out any other organic causes of the new symptoms.
Endoscopic features to identify a failed fundoplication was described by Jailwala
and coworkers, including presence of esophagitis, ease of endoscope passage
through the EGJ, location of wrap relative to diaphragmatic hiatus, location of the
squamocolumnar junction and the appearance of the wrap [53].
A competent fundoplication should give an endoscopic appearance, upon retroexion, a good seal around the endoscope by the wrap, and its resultant lengthened
intra-abdominal portion of the LES.
Compared with barium esophagography, endoscopy is able to pick up 10–15%
more structural abnormalities upon investigation for recurrence [53] whereas it is
less informative upon workup for dysphagia. However, uoroscopy is still
recommended in the planning of revision surgery as an image guide to the relative
anatomy of different structures.
Fig. 10.4 Barium esophagogram after fundoplication (reproduced with permission from ref. [52])
with the well-circumscribed lling defects seen around the narrowed distal esophagus, and a schematic diagram of the corresponding anatomy
160
Fig. 10.5 Barium esophagogram showing a slipped wrap, indicated by the arrows, and part of the
stomach is now above the wrap (reproduced with permission from ref. [52]). Schematic diagram
of corresponding anatomy
V. Wong et al.
Fig. 10.6 Barium esophagogram showing herniation of the whole fundoplication wrap above the
diaphragm (reproduced with permission from ref. [52]). The wrap is lled with contrast. Schematic
diagram of corresponding anatomy
10 Lower Esophageal Sphincter Efcacy Following Laparoscopic Antireux Surgery
161
10.5.3 Role ofHigh-Resolution Impedance-Manometry
Invariably for type I sliding hernia, the LES has moved through the diaphragmatic
hiatus and has herniated in the thoracic cavity [54]. High-resolution manometry can
identify what is sometimes referred to as the double hump or double high-pressure
zone [55]. This can be seen clearly in Fig.10.7. Evaluating hernia size indirectly
based on the distance between the double high-pressure zone on high-resolution
manometry tracings is fast coming the accepted practice in clinics globally [56].
This is very useful for general diagnosis and orientation of a hiatal hernia but it does
not give precise information on structure and function. It is recommended as part of
patient work up before surgery [57].
As high-resolution manometry has evolved over the last 20years so too has the
concept of intraluminal impedance and the combined concept of high-resolution
impedance manometry (HRIM). Studies have shown that intraluminal impedance
provides a much better understanding of the solid, liquid or gaseous state of the
reuxate [58]. However, although the technique has proven to be a useful tool in this
regard, and despite predictions on its development into clinical practice, this has not
Fig. 10.7 High resolution manometry tracing of a single swallow by a patient with a small size
hiatal hernia. The hernia is indicated by the spacing between the green color suggesting a higher
pressure where there is a squeeze present from the tone of the LES and the pinchcock effect of the
diaphragmatic hiatus. The X-axis represents time, Y-axis is position in the esophagus and color
represents pressure going from blue for low pressure through green toward red for high pressure.
Precise values are not shown as this gure is for illustrative purposes only
162
V. Wong et al.
materialized. Arguably it will not be useful to help diagnose patients with hiatal
hernia or the recurrence of GERD and hiatal hernia after antireux surgery [59].
This is mostly because repair of hiatal hernia by antireux surgery alters biomechanical activity in the region of the EGJ.As intraluminal impedance does not provide objective measures of function, it cannot directly evaluate improvements in the
junction barrier after surgery. Early information indicates that intraluminal impedance may have a role in assessing the acid pocket and this relates to the hypothesis
that in patients with hiatal hernia the acid pocket may appear in the hiatus [60].
Further studies need to be carried out to evaluate if using intraluminal impedance to
assess the makeup of the reuxate in the hiatus and to assess if this is altered,
improved, or eradicated after anti-reux surgery or to determine recurrence.
Since the physiological concept of TLESR is widely accepted and can currently be more easily assessed using high-resolution manometry, its assessment
role with respect to hiatal hernia patients is worth a mention [61]. However, studies back in the year 2000 are conicting. Van Herwaarden and coworkers claimed
that TLESRs in patients with HH were comparible to those without HH and in the
same year and journal Kahrilas and coworkers claimed TLESRs were increases in
patients with GERD and hiatal hernia [62, 63]. However, there is no evidence
from the literature of TLESR evaluation being important before or after antireux
surgery to evaluation efcacy. This of course makes some sense since very often
it is not a lack of tone or pressure in the LES that is observed with hiatal hernia but
a separation on the two main mechanism of the barrier, i.e. the LES and the crural
diaphragm.
10.5.4 Role oftheFunctional Luminal Imaging Probe
New work using the functional luminal imaging probe (FLIP) to measure function
in the region of the LES and the wider EGJ segment suggests it may have a role in
antireux surgery in general and in the evaluation of hiatal hernia in particular. In
brief FLIP provides serial measures of cross-sectional areas inside a long bag and
the lumen geometry and distensibility can be derived from the measurements.
De Haan and coworkers provided some insights into the role of FLIP in the
evaluation of reux surgery, Nissen and Toupet in a series of 75 patients (48 of
which were redos). The authors suggested that there is ongoing variability in the
outcomes of antireux procedures despite their existence for more than 50years.
This has hampered the ability to assess adequately predictors of clinical and symptomatic outcomes. In their study they showed that the esophagogastric segment is
less distensible after anti-reux surgery and that Nissen procedures are less distensible than Toupet procedures. Based on this they suggested FLIP provides a method
to tailor fundoplication distensibility by observing geometry and pressure intraoperatively. Although further studies are needed, this could help create more uniformity in technique, improve the long-term symptomatic outcomes and further
minimize side effects [64].